Recent progress and perspective for oxygen evolution reaction under acidic environments

Proton exchange membrane (PEM) electrolyzers play a vital role in sustainable energy conversion and storage. However, the oxygen evolution reaction (OER) is considered to be their major bottleneck, limiting their overall efficiency due to its sluggish kinetics and vulnerability under acidic and oxidative conditions. Furthermore, it is still a challenge to design and develop competent and robust electrocatalysts for OER in acidic media. In this case, achieving the rational design of high-performance OER catalysts relies on a comprehensive understanding of the reaction mechanism and structure-activity relationships. In this review, we address the recent progress on the OER mechanisms, including the deactivation mechanisms, scaling relations, and electronic descriptors of OER catalysts with the help of theoretical computations and advanced operando characterization. Then, the strategies for enhancing the OER performance and stability of catalysts are introduced. Finally, the representative catalysts ranging from noble metal-based catalysts and transition metal-based catalysts to metal-free catalysts reported in the last five years for acidic OER are described, followed by a future perspective for developing OER catalysts. Proton exchange membrane (PEM) electrolyzers play a vital role in sustainable energy conversion and storage.